20121221022210 has 256 divisors, whose sum is σ = 67270263091200. Its totient is φ = 4157674444800.

The previous prime is 20121221022103. The next prime is 20121221022233. The reversal of 20121221022210 is 1222012212102.

It is a happy number.

20121221022210 is a `hidden beast` number, since 20 + 1 + 212 + 210 + 2 + 221 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1017970 + ... + 6424850.

It is an arithmetic number, because the mean of its divisors is an integer number (262774465200).

Almost surely, 2^{20121221022210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20121221022210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33635131545600).

20121221022210 is an abundant number, since it is smaller than the sum of its proper divisors (47149042068990).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20121221022210 is a wasteful number, since it uses less digits than its factorization.

20121221022210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5407094 (or 5407088 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 20121221022210 its reverse (1222012212102), we get a palindrome (21343233234312).

The spelling of 20121221022210 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty-one million, twenty-two thousand, two hundred ten".